Preparation And Performance Evaluation Of N-Heptane Isomerization Catalyst

With the increasingly prominent of environment problems,currently the demands for cleaning oil is kept expanding.Consequently,the isomerization of n-alkane has been paid more and more attention by researchers.Ni/HZSM-5 and Ni-P/HZSM-5 catalysts were prepared by impregnation method,and were characterized by the means of XRD?BET?SEM and Py-IR.Using n-heptane as raw material,the activity?isomerization selectivity and stability of the two catalysts were investigated in a fixed bed reactor.The effect of technological conditions on the isomerization of n-heptane was also studied.The results show that the active metal of two catalysts dispersed homogeneously on the support surface,molecular sieve have higher crystallinity and better crystal structure.Under the optimal conditions of reaction temperature 230??pressure 1.0MPa and WHSV 1.0h^-1,two kinds of catalysts have excellent performance of isomerization,hydroisomerization products of n-heptane on Ni/HZSM-5 and Ni-P/HZSM-5 are mainly2-Methylbutane?3-Methylhexane?2,2-Dimethylpentane and 2,3-Dimethylpentane.The results of hydroisomerization of n-heptane showed that increase the reaction temperature can increased the conversion of n-heptane,but not favor to the improvement of the selectivity of n-heptane isomerization;to improve the reaction pressure properly is beneficial to the conversion and isomerization selectivity of n-heptane;low weight space velocity is in favor of increasing conversion of n-heptane,but not conducive to the improvement of the selectivity of n-heptane isomerization;The conversion and isomerization selectivity of n-heptane are promoted as the ratio of hydrogen to oil increased.